The sun may be setting on South Africa's gold industry, but 3.8km below the surface, Harmony Gold is hitting pay dirt. The company's full-year earnings soared by 60%, lifted by higher prices and a significant increase in grades at Mponeng, the world's deepest mine, where Harmony may yet go further underground.

Harmony bought Mponeng, the world's deepest mine which extracts gold as far down as 3.8km, from AngloGold Ashanti in early 2020 for $200-million.

It has not had any buyer's remorse and the acquisition had already paid for itself by last year.

Harmony unveiled a 60% surge in full-year headline earnings on Wednesday to 800 cents per share, resulting in a final dividend of 75 cents per share. Mponeng played a starring role on this stage, with a staggering 16% increase in recovered grades, leading to a 22% rise in production to almost 240,000 ounces.

"We expected to go into the higher-grade parts of the mine two or three years after we bought it," Harmony CEO Peter Steenkamp told Daily Maverick.

Overall, group earnings climbed by 14% to R47.5-billion, while overall, grades increased by 8%. Combined with a 15% spike in the average gold price received to $1,808 an ounce, the end result was a flow of cash to the company's bottom line. This has bucked the trend among South African mining companies, notably in the PGM space, which have generally reported a significant fall in earnings this year.

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